Best open-source alternatives to Microsoft 365

TinyCld is a self-hosted workspace platform organized as an app shell plus separately installable feature packages. It is designed for users who want a modular alternative to a hosted productivity suite, with core capabilities such as mail, calendar, contacts, drive, text, calc, and import tooling assembled from sibling packages in a pnpm workspace. The project combines an Expo front end, PocketBase back end, and Go server wiring, with a generator that connects the installed packages into routes, seeds, migrations, and runtime configuration. It is aimed at developers or operators who want to assemble and run a customizable workspace locally or in a self-hosted deployment, with Docker-based delivery and a documented bootstrap flow for building a working workspace root.